This example demonstrates a single, small circle that follows the mouse cursor across an SVG canvas. Built with React, it uses the `useState` hook to store the cursor’s client coordinates and the `useCallback` hook to define the `onMouseMove` event handler, which updates those coordinates on every mouse movement. The view renders a yellow smiley face (a face with eyes and a mouth) as a static SVG background, while the movable circle acts as an interactive pointer. The code relies on React’s `ReactDOM.render` to mount the component into the page’s root element.